Lawmakers on Capitol Hill have a busy week ahead, starting with an expectedly confrontational hearing on Monday on the confirmation of John Bolton (search ) as U.S. ambassador to the United Nations.

Bolton, the undersecretary for arms control and international security at the State Department, will face unrelenting Democrats on the Senate Foreign Relations Committee (search). They say Bolton, who has served the last three Republican presidents and is a strong supporter of overhauling the United Nations, is considered too antagonistic and adversarial to represent the United States at the world body.

Democratic Sen. Joseph Biden of Delaware, the ranking member of the committee, has said he intends to grill Bolton about a variety of issues, specifically on reports alleging that Bolton pressured intelligence agents on pre-war weapons of mass destruction (search) reports.

"I think it's a bad idea to have a man there who doesn't have much regard for the U.N.," Biden told a Sunday morning cable news show, adding that he would vote against Bolton's confirmation.

Senate Democrats are basing part of their opposition on a two-year-old Senate Intelligence Committee report that questioned whether Bolton overstated Cuba's weapons technology and transfers even though intelligence analysts warned that the information should not be publicly disclosed and that Bolton was hyping the case.

Cuba has denied having weapons of mass destruction or sending technical expertise to enemies of the United States.

In addition, Biden, along with the seven other Democrats on the committee, said he plans to introduce "new evidence" against Bolton showing he "pressured intelligence analysts" because they didn't agree with him. Democrats have requested an unusual second-day hearing on Tuesday with a witness who they believe will verify those reports.

One Democratic committee aide told Fox News that the case against Bolton will be “highly specific” and will emphasize “not that he’s unilateral, not that he doesn’t like the U.N. … What counts now is that he may have intimidated intelligence officials,” making him unreliable when it comes to helping secure the United States.

Committee chairman Richard Lugar, R-Ind., however, said he has read carefully the transcripts from the Intelligence Committee interviews and did not see evidence Bolton intimidated analysts. He added that Bolton's gruff manner, succinct criticism for the United Nations and blunt remarks should not prevent him from serving.

"These are not, in my judgment, disqualifiers for a presidential nominee who is going to the U.N. to create reform," Lugar said on a Sunday cable news show.

Sen. Rick Santorum, R-Pa., added words of praise for Bolton, saying he had an "exemplary record."

"I think he's the right man for the U.N. because he brings the kind of candor that you need to an organization that's got a lot of trouble, does not have a lot of support here in the United States, does not have a lot of support in the Congress, particularly the Republican side," added Santorum, speaking on another Sunday talk show. Santorum is not a member of the Foreign Relations Committee.

With a 10-8 Republican majority on the panel, support for Bolton is likely to push his confirmation out of the committee process to a Senate floor vote. All 10 Republicans on the committee have indicated their support for the nominee, and unless "something truly damaging" is revealed at the hearings, Bolton is likely to make it to a full Senate vote on party lines, said Sen. Chuck Hagel, a member of the committee.

But Democrats say they need only one Republican committee member to oppose Bolton to end up with a tied 9-9 vote, thereby preventing his nomination from going to a full Senate vote. That one GOP committee member could be Sen. Lincoln Chafee, who late last week said he would likely support Bolton but with the caveat that he would switch his vote if new damning evidence were to emerge.

Lugar spokesman Andy Fisher said the chairman hopes to hold the confirmation vote on Thursday. If Bolton is confirmed by the panel, Senate Majority Leader Bill Frist will decide when the nomination gets a floor vote.

Asked whether he would consider joining a filibuster of Bolton if he is approved by the panel, Senate Democratic Leader Harry Reid of Nevada said he wanted to see how the committee hearing played out.

"He doesn't appear to be the best guy for the job, but let the committee work on this," Reid told a Sunday news show.

Republican strategist Paul Manafort told FOX News that Democratic opposition to Bolton represents more of a protest against the 2004 election results than an attack on Bolton's abilities.

"These are people who represent the philosophy of the administration that won the election in November, and the Democrats are trying not to oppose the candidates by virtue of their qualifications but by virtue of what they stand for, and they lost that election," Manafort said. "John Bolton is more than qualified to be U.N. ambassador."

Democratic strategist Bob Beckel said that in the end he didn't think Democrats would try to mount a filibuster or other type of procedural block to Bolton.

"They've stirred up a few things but they're not going to break a pick on it. He's going to get approved and he's going to be at the U.N. and at that point we'll see," Beckel told FOX News.

If confirmed, Bolton will succeed former Sen. John Danforth, who resigned last year after six months in New York.

FOX News' Sharon Kehnemui Liss and Molly Hooper and The Associated Press contributed to this report.